In hospitals, nursing home facilities and the like, injection of medicament into the body tissues of patients is done on a daily basis. Typical hypodermic syringes are provided with a barrel having a needle that is fixed or removably attached at one end thereof. A plunger typically having an elastomeric piston is movable within the barrel to load the barrel with liquid medicament by suction as the plunger and piston are moved within the barrel in a direction away from the needle. After the needle has penetrated the body tissues of the patient, as the direction of movement of the plunger and piston are reversed and the piston is forced toward the needle, medicament contained within the barrel will be injected through the needle into the body tissues.
After hypodermic syringes have been used in this manner, those syringes that are disposable present a significant problem to the hospital or nursing home staff because the possibility of inadvertent needle pricks subject nursing personnel to the possibility of cross-contamination by virile or bacterial contaminants that might be present on the needle after its use. In an effort to avoid the possibility of inadvertent needle pricks special waste containers are often provided at hospital facilities into which the used disposable hypodermic syringes are placed. These containers and the syringes contained therein are then disposed of in a specifically organized manner to insure against the possibility of inadvertent infectious contamination of nursing personnel. Further, refuse handlers and other persons who might inadvertently come into contact with the used hypodermic syringes are also subject to the same hazards. Often times the needles themselves are bent over so as to minimize the possibility of inadvertent needle pricks and to preclude the possibility of subsequent use of disposable hypodermic syringes.
In emergency conditions, such as during use by paramedics in ambulances during transportation of patients to trauma centers, various medicaments are injected into patients by paramedics under the direction of medical staff personnel. To minimize the possibility of inadvertent pin pricks by used hypodermic syringes and to enhance the speed of the emergency care being accomplished, the paramedic staff will often toss used hypodermic syringes onto the floor of the emergency vehicle such that the syringes are out of the way of both the patient and the paramedics. After the emergency has ended and these syringes are manually recovered for disposal, there is the possibility that inadvertent needle pricks will occur. It is of course desirable to provide a suitable facility for protecting nursing personnel, paramedics and other persons from the hazards of inadvertent needle pricks as they go about their daily tasks.
It is known that in the past hypodermic syringes have been disposed of by dumping the same, together with other hospital refuse at certain locations in the ocean. Not only is this hazardous to the marine environment because of the presence of the hypodermic syringes and medical contaminates in the ocean and the possibility of cross-contamination that might occur, it is well known that used disposable syringes and other medical refuse tends to wash up on the beaches where it becomes a hazard to persons, especially children, that might be present at the beach.
It is desirable, therefore, to provide a hypodermic syringe that includes a facility for rendering the needle thereof to a protected, completely encapsulated condition such that it can not possibly cause an inadvertent needle prick at any time during its handling or during its disposal. It is desirable to provide a hypodermic syringe having the capability of retracting the needle to a position inside the barrel of the syringe and locking the needle in its retracted position so that the needle of the hypodermic syringe is always enclosed after its use, thus precluding the possibility that the needle might cause an accidental needle prick as the syringe is subsequently handled. It is also desirable to provide a hypodermic syringe of the disposable type that is provided with facility for rendering it completely inoperative such that it can not be subsequently used.